Zane H. Healy wrote: I have an Emulex UC18 (dual SCSI, one channel setup for MSCP disk, other setup for TMSCP tape) on my PDP-11/44. I have both 2.1GB Seagate hard drives and DEC RRD43 (Toshiba) CDROMs on the disk port. I've used the CDROM to boot XXDP, RT-11, BSD2.11, and RSTS. The Emulex reads the CDROM and reports the size of the disk as the size of the drive. If no disk is present it reports drive offline. I can mount/unmount (BSD) and switch media in the CDROM at will.

Zane H. Healy wrote: I found this to be *really* useful to check out hardware; all the diagnostics are right there. With a SCSI CDROM on an MSCP controller, XXDP boots and runs fine. It does not by default require any write access to the device media. XXDP v2.5 supports MSCP, so it was really a no-brainer. I just used CDRWIN on a PC to burn an ISO CD from the XXDPv2.5 RL02 .dsk image. I built and run 2.11BSD under SIMH (2.11 supports MSCP controllers) on a 1GB virtual MSCP drive. The root/swap/usr filesystems all were configured to fit in well under 650MB, so I can just copy the first part of the .dsk to an ISO CD using the same process above. On the real 11/44, I then booted XXDP, did a device to device copy of the first 32MB (XXDP copy limit: 64K 512B blocks) and then booted BSD from the hard drive. From there I can 'dd' and 'mkfs' the rest of the partitions, and boot all the way up to a network ready system since I have a DEUNA on the 11/44. RT-11 of course will boot and run directly off the CDROM. It is happy with a R/O boot media, as is XXDP. For RSTS I am running a v9.2 sysgen under SIMH with the same MSCP config to that used for BSD above. When I copied the image to CDROM, it would boot but failed the device config (it autodetects the TU58 serial port and sets the vector at 300) but SIMH does not support this device, so the sysgens did not match :-( and RSTS croaked in the boot phase. I have since hacked by BSD config, RSTS config, SIMH config, and my real h/w config to place my DZ11A at vector 310 (instead of 300) so all the environments are now consistent (BSD was not seeing the TU58 DL11 before). However I haven't yet gone back to try and reboot the updated RSTS config on the real 11/44. I have also stumbled across another problem. In trying to image copy 600+MB CDROMs to 1GB hard drives I have found that both XXDP and RT-11 appear to copy only the first 32MB (65536*512B total), so I can't copy my entire RSTS disk image to the hard drive. BSD won't do it either, since as of 2.11BSD it uses the on-disk partition map to determine the size of the disk, and a RSTS disk image does not have the BSD partition map. If anyone has a solution I'd like to hear it. At this point I'm about to write a simple standalone MSCP device/device copy routine that I can boot from TU58 and copy the entire 650MB CDROM to the 1GB disk.